EP0100754B1

EP0100754B1 - Method for making a spectacles resilient hinge

Info

Publication number: EP0100754B1
Application number: EP83830154A
Authority: EP
Inventors: Piero Consolati
Original assignee: Individual
Current assignee: Individual
Priority date: 1982-07-30
Filing date: 1983-07-25
Publication date: 1987-01-14
Also published as: IT1153157B; IT8222691A1; ATE24972T1; US4570289A; CA1212530A; DE3369200D1; EP0100754A3; EP0100754A2; IT8222691A0

Abstract

The method comprises the steps of making a hinge by using conventional materials and treatments and applying, on the edge of the hinge provided for contacting and biassing a ball member, one or more cup members, made of a hard metal material and effective to provide a cam profile configuration.

Description

The present invention relates to a method for making resilient hinges for spectacles.
As it is well known, resilient hinges for spectacles frames are presently commercially available which allow for the spectacles arms to be resiliently gradually biassed with respect to the spectacles frame front portion owing to the provision of resilient biassing means acting on a suitably shaped cam profile.
In particular resilient hinges are known of the so-called double action type, i.e. effective to provide a resilient reaction both in the arm opening step (that is with the spectacles arm parallel to one another during the use) and in the arm closure step, with the spectacles arm in a closed condition at rest.
The operating principle of the mentioned hinges is that of the resilient reaction provided by a cam profile on which a ball member is caused to slide as biassed by a spring.
In order to obtain an efficient and proper resilient reaction it is required that the cam member cooperating with said ball member, be made from a high hardness material.
In fact, if the hardness of said material is a poor one, the ball member would be susceptible to penetrate into the cam surface, thereby impairing the cam effect thereof, because of wear.
Thus the mentioned cam member is generally made starting from hardened steel or a sintered material.
On the other hand, these materials are affected by practical drawbacks, since they are necessarily to be subjected to protecting treatments; moreover they may be hardly processed to obtain the desired shapes and coupling to other components of the frame.
More specifically, as thereinabove stated, the pieces made starting from the mentioned materials are to be suitably processed in order to prevent said pieces from being quickly oxidated.
The protecting covering layer, on the other hand may be obtained only by carrying out determined processing steps (for example sealing of the steel cam member to the front of the spectacles frame) and, accordingly, other portions of the spectacles are affected, with consequent increased costs.
Moreover, a steel material may be hardly machined by tools particularly as the conventional method for making not resilient hinges is used.
It should also be noted that presently available spectacles are provided with nickel silver hinges so shaped as to allow for the spectacles arm to be adjusted in its slant, in order to fit the spectacles to the user face.
On the other hand, the steel cam member is made in a single piece with the spectacles front portion, thereby it may be hardly subjected to modifications.
With respect to the applying and coupling features, it should be noted that, in plastics spectacles, the anchoring blade embedded in the spectacle front portion, acts as a cutting blade susceptible to cut through the spectacles as the latter are stressed during the use or because of temperature variations.
Moreover, because of contingent requirements, that is because of constructional reasons, the cam member is arranged at the outermost end of the spectacle frame, jointly to the front portion action as an insert, thereby facilitating possible breakages.
For example, the document DE-A-2003776 discloses a spectacle hinge wherein the cam member engaging with the ball is made of a not particularly hard material, thereby this hinge is affected by a quick-wear of the cam- ball engaging surfaces.
On the other hand the document EP-A-6 075 addresses the problem of reducing the wear of the cam member profile but it solves that problem by a rather complex and expensive structure, that is by interposing a reduced friction member between the hinge ball and the ball biasing spring.
Accordingly, the object of the present invention is that of overcoming the above-mentioned drawbacks by providing a method for making spectacle resilient hinges of the cam profile and spring biased ball type which may be carried out easily and at a reduced cost and wherein there is eliminated the need of carrying out protecting surface treatments on the produced hinges, in particular on the cam profile thereof.
According to the present invention the above is achieved by a method for making resilient spectacle hinges of the cam profile and spring biased ball type, comprising the steps of making the cam of the hinge out of conventional not particularly hard materials without any special treatment, characterized in that it further comprises fixing, on the edge of said cam intended for contacting and biasing said ball, one or more cup members, made of a hard material and effective to provide the necessary cam profile.
The characteristics and advantages of the method for making spectacles resilient hinges according to the present invention will become more apparent thereinafter from the following detailed description of some embodiments thereof, with reference to the accompanying drawings, where:

Fig. 1 illustrates the portion of a hinge, for plastics material spectacle frame, provided for housing the hard metal cup members;
Figs. 2 and 3 illustrate two bifurcated members, respectively of a metal material, in single piece with the arm, and of a plastics material, effective to be rotatively coupled to the mentioned hinge portion;
Fig. 4 illustrates a sectional member substantially reproducing the contour of the mentioned hinge portion;
Fig. 5 illustrates a plate member which the hinge portion of Fig. 1 may be obtained;
Fig. 6 illustrates preferred embodiments of the hard metal cup members;
Fig. 7 illustratively shows a possible procedure for coupling the cup members and hinge;
Fig. 8 illustrates some embodiments of a hinge provided for metal frames, effective to house the mentioned cup members;
Fig. 9 illustrates the coupling between a spectacles front portion and a plastics material arm, obtained by means of a hinge produced by the subject method;
Fig. 10 is a horizontal cross-sectional view of the mentioned coupling;
Fig. 11 illustrates a further coupling between a . spectacles front portion and arm, in a metal frame;
Fig. 12 is a horizontal cross-sectional view of the coupling shown in Fig. 11; and
Fig. 13 illustrates a resilient spectacles hinge according to the present invention, wherein the hinge portion rigid with the frame is made in a single piece with the spectacle frame itself.

With reference to the figures of the accompanying drawings, an embodiment of the method for making resilient hinges for spectacles according to the present invention comprises the step of providing a small plate member 1, which is essentially provided with an edge 2 to which shaped members made of a hard metal material may be firmly coupled, as well as a portion 3, also suitably shaped, effective to allow for said members to be locked either on the front portion or on an arm of the spectacles frame.
More specifically, the mentioned plate may be obtained either by cutting a member 4 (Fig. 4) of suitable cross-section, or by shearing a blade member 5, made of an easily machinable material such as nickel silver.
That same plate will be obviously subjected to suitable conventional processing steps, in order to form therein a portion 6 provided with a through going hole 7, effective to be rotatively coupled, through a threaded member 8, to the two legs of a bifurcated member 9 forming the spectacles arm end portion.
On the edge 2 of the mentioned plate there are formed two counterbores 10, effective to hold corresponding cup members, made of stainless steel or of a sintered material, which may be provided with a spherical 11 or not spherical surface 11', or with two flat converging surfaces 1" depending on the requirements.
More specifically, the counterbore 10 wherein the outer cup is housed may be threaded in such a way as to allow for the related cup, also threaded on its cylindrical outer surface, to vary the position of the spring biassed ball, in such a way as to provide different angular positions of the spectacles arm at the opening dead point.
In this connection it should be noted that the mentioned counterbores, providing holding seats for said cups 11, are preferably made on slanted surfaces in order to allow for the arms to be set in a parallel relationship, as well as for providing gradual resilient reactions, during the arm opening and closing movements, thereby allowing for the outer cup to act as an opening stroke stop member.
The anchoring of the individual cup members in their seats may be obtained, as it is schematically illustrated in Fig. 7, by using mushroom cup members and deforming the housing of the stem 12, or by caulking the edge 13 of the mentioned counterbores on the cup convex portion, or by bending the edge of said counterbores on an abutment member as perimetrically formed with respect to the cup, all along the extension 14 thereof, or at a single sector 14'.
It should also be noted that the anchoring of said cups in their seats may also be obtained by other like methods, such as glueing methods and the like.
The mentioned cups engage with a ball member 15 (Figs. 10, 12) biassed by a spring 16, which are housed in a suitable cylindrical seat 17, as formed along the axis of the rod 18 and being open at the bifurcated portion 9 forming the end portion of said rod or arm.
In this connection it should also be noted that, since the contacting surfaces of the ball and cam members are in actual practice both of spherical configuration, the friction therebetween is reduced to a minimum, thereby providing even and precise movements of the arms.
In particular, the above cam member supporting plate may be also formed directly in the spectacles frame (both arm portion and front portion), as it is shown in Fig. 13, preferably in metal material frames, but also in molded plastics material frames, provided that the latter be provided with suitable hardness characteristics.
The latter approach is made possible by the fact that the resilient reaction force is supported by the two cup members, without affecting other portions of the hinge.
Moreover, it should be apparent that the cam member may be fixed to the spectacle arm and the ball-spring assembly may be located in the portion fixed to the spectacle front portion.
From the above disclosure and figures of the accompanying drawings there are self-evident the great constructional simplicity and the possibility of producing a broad range of spectacles frames characterizing the method for making resilient hinges for spectacles according to the present invention.
In fact, in the method, the hinge is processed as a conventional hinge and it becomes "resilient" at the last stage, as the shape thereof has been already defined, since the cup members may be applied during a last assembling step, with the hinges already applied to the spectacles frame.
In other words, before applying the screw for coupling pivotally the spectacles arm and front portion, it will be possible to affix the cup members by means of one of the methods illustrated above.
While the subject method has been disclosed and illustrated by way of an indicative and not limitative example, it will be clear that it is susceptible to several modifications and variations.

Claims

1. A method for making resilient spectacle hinges of the cam profile and spring biased ball type, comprising the steps of making the cam of the hinge out of conventional not particularly hard materials without any special treatment, characterized in that it further comprises fixing, on the edge of said cam intended for contacting and biasing said ball, one or more cup members, made of a hard material and effective to provide the necessary cam profile.

2. A method according to Claim 1, characterized in that it comprises the step of making a plate member having an edge to which the cup members, made of hard metal, are firmly coupled, and a portion, opposite to said edge and shaped to allow for said plate to be locked in the front portion or arms of the spectacles, said plate being made by cutting through a suitably profiled block or by cutting it out of plate material made of easily machinable material, such as nickel silver.

3. A method according to Claim 1, characterized in that the edge of said plate is formed with counterbores effective to hold the corresponding cup members, the cup members being made of stainless steel or a sintered material, and being provided with a spherical surface or with two flat converging surfaces.

4. A method according to Claim 3, characterized in that said counterbores are formed on slanted surfaces, the outer cup member being effective to act as an opening stop member.

5. A method according to Claim 3, characterized in that said cup members are anchored in the related seats by using mushroom shaped cup members and deforming the seat housing the stem thereof; or by caulking the edge of said counterbores on the convex portion of said cup members; or by bending the edge of said counterbores against an abutment portion perimetrically formed on said cup members, all along the circumference thereof or at an individual sector thereof; or by glueing.

6. A method according to Claim 1, characterized in that said spring and said ball are housed in a cylindrical seat formed along the axis of the spectacle arm and open at a bifurcated portion forming the end portion of said arm.

7. A method according to Claim 1, characterized in that said cam profile supporting plate is directly formed on the spectacle arm orthe spectacle front portion in metal frames or in molded plastics frames.

8. A method according to Claim 1, characterized in that the cam is fixed to the spectacle arm and the ball-spring assembly is located in the portion fixed to the spectacles front portion.

9. A method according to Claim 1, characterized in that an outer cup member is coupled to the hinge body by means of a thread, to allow for the spectacle arm to be angularly adjusted at the opening dead point thereof.

10. A resilient hinge for spectacles, made by the method according to Claim 1, characterized in that the ball-cam profile contacting surfaces are of substantially spherical shape.